1,721,007 research outputs found

    Quantum Techniques in Machine Learning

    No full text
    In the last few years, we have witnessed an increasing interest in bridging two impor- tant research areas that fundamentally changed our way and abilities of processing information, namely Machine Learning and Quantum Computation. In the Summer 2017, we had the idea of inviting major experts in Quantum Compu- tation and Information on the one hand, and in Machine Learning and Optimisation on the other hand, for a meeting at the University of Verona to discuss the latest advances in the newly born field of Quantum Machine Learning. The idea developed in a very successful workshop, bringing together more than hun- dred scientists to attend and/or contribute their results on the two-way interaction between Machine Learning and Quantum Computation, aimed at demonstrating how the intersection of the two fields can offer great potential for both. This special issue is dedicated to this event, which was held in Verona on 6-8 November 2017 under the name of QTML 2017 - 1st Workshop on Quantum Techniques in Machine Learning. It represents the first of a series of workshop that are now held yearly in diverse places worldwide. The volume collects original contributions focused on the following topics and not limited to the works presented at QTML 2017: - Quantum computing for enhancing machine learning algorithms - Machine learning techniques for the analysis of interacting quantum systems - Quantum entanglement and topology for the efficient representation of quan- tum systems - Approaches to machine learning based on Topological Quantum Computation - Algorithmic techniques for quantum optimisation (e.g. quantum annealing). We wish to thank all the people who contributed to bringing this special issue to completion. In particular, we are very grateful to the reviewers who provided a valuable help to ensure the high quality of the papers, to the authors for the scrupu- lous work in improving their papers following the reviewers' suggestions, and to all the participants in QTML 2017 whose lively discussions and critical interventions greatly inspired the authors

    Quantum computers,Computer quantistici

    No full text
    A cosa serve un computer quantistico e come si puo' realizzare fisicament

    On Quantitative Analysis of Probabilistic Protocols

    No full text
    We advocate the use of approximate noninterference for the security analysis of probabilistic protocols. Our approach relies on a formalisation of the protocol in the setting of a probabilistic process algebra and a notion of process similarity based on weak probabilistic bisimulation. We illustrate this approach by presenting the analysis of a probabilistic nonrepudiation protocol which allows us to quantitatively estimate its fairness degree

    Molecular junctions enhancing thermal transport within graphene polymer nanocomposite: A molecular dynamics study

    Full text link
    Thermal conductivity of polymer-based (nano)composites is typically limited by thermal resistances occurring at the interfaces between the polymer matrix and the conductive particles as well as between particles themselves. In this work, the adoption of molecular junctions between thermally conductive graphene foils is addressed, aiming at the reduction of the thermal boundary resistance and eventually lead to an efficient percolation network within the polymer nanocomposite. This system was computationally investigated at the atomistic scale, using classical Molecular Dynamics, applied the first time to the investigation of heat transfer trough molecular junctions within a realistic environment for a polymer nanocomposite. A series of Molecular Dynamics simulations were conducted to investigate the thermal transport efficiency of molecular junctions in polymer tight contact, to quantify the contribution of molecular junctions when graphene and the molecular junctions are surrounded by polydimethylsiloxane (PDMS) molecules. A strong dependence of the thermal conductance was found in PDMS/graphene model, with best performances obtained with short and conformationally rigid molecular junctions. Furthermore, the adoption of the molecular linkers was found to contribute additionally to the thermal transport provided by the surrounding polymer matrix, demonstrating the possibility of exploiting molecular junctions in composite materials

    Estimating the Maximum Information Leakage

    Full text link
    Preventing improper information leaks is a greatest challenge of the modern society. In this paper we present a technique for measuring the ability of several families of adversaries to set up a covert channel. Our approach relies on a noninterference formulation of security which can be naturally expressed by semantic models of program execution. In our analysis the most powerful adversary is measured via a notion of approximate process equivalence. Even if finding the most powerful adversary is in general impractical, we show that this requires only a finite number of checks for a particular family of adversaries which are related to a probabilistic information flow property

    Noninterference and the Most Powerful Probabilistic Adversary

    No full text
    Probabilistic noninterference extends the classical possibilistic notion introduced by Goguen and Meseguer in order to capture the information leakage caused by adversaries that set up probabilistic covert channels. In this setting we investigate how to evaluate the observational power of an adversary to the purpose of establishing the maximal security degree of a given system. We introduce three classes of probabilistic adversaries, which represent the different observational power of an adversary, and then we establish properties for each such classes which state the complexity of effectively computing the most powerful adversary

    PERSISTENT HOMOLOGY ANALYSIS OF MULTIQUBIT ENTANGLEMENT

    Full text link
    We introduce a homology-based technique for the classification of multiqubit state vectors with genuine entanglement. In our approach, we associate state vectors to data sets by introducing a metric-like measure in terms of bipartite entanglement, and investigate the persistence of homologies at different scales. This leads to a novel classification of multiqubit entanglement. The relative occurrence frequency of various classes of entangled states is also shown

    A Quantitative Approach to Noninterference for Probabilistic Systems

    No full text
    We present a technique for measuring the security of a system which relies on a probabilistic process algebraic formalisation of noninterference. We define a mathematical model for this technique which consists of a linear space of processes and linear transformations on them. In this model the measured quantity corresponds to the norm of a suitably defined linear operator associated to the system. The probabilistic model we adopt is reactive in the sense that processes can react to the environment with a probabilistic choice on a set of inputs; it is also generative in the sense that outputs autonomously chosen by the system are governed by a probability distribution. In this setting, noninterference is formulated in terms of a probabilistic notion of weak bisimulation. We show how the probabilistic information in this notion can be used to estimate the maximal information leakage, i.e. the security degree of a system against a most powerful attacker
    corecore